mirror of
https://github.com/ekeeke/Genesis-Plus-GX.git
synced 2024-12-25 18:51:49 +01:00
439 lines
11 KiB
C
439 lines
11 KiB
C
/*
|
|
Copyright (C) 1999, 2000, 2001, 2002, 2003 Charles MacDonald
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include "shared.h"
|
|
|
|
#define CLOCK_NTSC 53693175
|
|
#define CLOCK_PAL 53203424
|
|
#define SND_SIZE (snd.buffer_size * sizeof(int16))
|
|
|
|
t_bitmap bitmap;
|
|
t_snd snd;
|
|
uint32 aim_m68k = 0;
|
|
uint32 count_m68k = 0;
|
|
uint32 dma_m68k = 0;
|
|
uint32 aim_z80 = 0;
|
|
uint32 count_z80 = 0;
|
|
uint16 misc68Kcycles = 488;
|
|
uint16 miscZ80cycles = 228;
|
|
uint16 lines_per_frame = 262;
|
|
double CPU_Clock = (double)CLOCK_NTSC;
|
|
void *myFM = NULL;
|
|
static int sound_tbl[312];
|
|
static int sound_inc[312];
|
|
uint8 alttiming = 0;
|
|
|
|
void m68k_run (int cyc)
|
|
{
|
|
/* cycles remaining to run for the line */
|
|
int cyc_do = cyc - count_m68k;
|
|
|
|
/* 68k is not frozen */
|
|
if (cyc_do > 0)
|
|
{
|
|
/* interrupt handling */
|
|
if (vint_pending && (reg[1] & 0x20)) m68k_set_irq(6);
|
|
else if (hint_pending && (reg[0] & 0x10)) m68k_set_irq(4);
|
|
if (cyc_do > 0) m68k_execute(cyc_do);
|
|
count_m68k += cyc_do;
|
|
vint_pending = 0;
|
|
}
|
|
}
|
|
|
|
void z80_run (int cyc)
|
|
{
|
|
int cyc_do = cyc - count_z80;
|
|
if (cyc_do > 0) count_z80 += z80_execute(cyc_do);
|
|
}
|
|
|
|
void m68k_freeze(int cycles)
|
|
{
|
|
extern int m68ki_remaining_cycles;
|
|
int extra_cycles = cycles - m68k_cycles_remaining();
|
|
|
|
if (extra_cycles > 0)
|
|
{
|
|
/* end of 68k execution */
|
|
m68ki_remaining_cycles = 0;
|
|
|
|
/* extra cycles to be burned at next execution */
|
|
count_m68k += extra_cycles;
|
|
}
|
|
else m68ki_remaining_cycles -= cycles; /* we burn some 68k cycles */
|
|
}
|
|
|
|
extern uint8 hq_fm;
|
|
int audio_init (int rate)
|
|
{
|
|
int i;
|
|
int vclk = (int)(CPU_Clock / 7.0); /* 68000 and YM2612 clock */
|
|
int zclk = (int)(CPU_Clock / 15.0); /* Z80 and SN76489 clock */
|
|
|
|
/* Clear the sound data context */
|
|
memset (&snd, 0, sizeof (snd));
|
|
|
|
/* Make sure the requested sample rate is valid */
|
|
if (!rate || ((rate < 8000) | (rate > 48000))) return (0);
|
|
|
|
/* Calculate the sound buffer size */
|
|
snd.buffer_size = (rate / vdp_rate);
|
|
snd.sample_rate = rate;
|
|
|
|
/* Allocate sound buffers */
|
|
if (FM_GENS)
|
|
{
|
|
snd.fm.gens_buffer[0] = realloc (snd.fm.gens_buffer[0], snd.buffer_size * sizeof (int));
|
|
snd.fm.gens_buffer[1] = realloc (snd.fm.gens_buffer[1], snd.buffer_size * sizeof (int));
|
|
if (!snd.fm.gens_buffer[0] || !snd.fm.gens_buffer[1]) return (-1);
|
|
memset (snd.fm.gens_buffer[0], 0, SND_SIZE*2);
|
|
memset (snd.fm.gens_buffer[1], 0, SND_SIZE*2);
|
|
}
|
|
else
|
|
{
|
|
snd.fm.buffer[0] = realloc (snd.fm.buffer[0], snd.buffer_size * sizeof (int16));
|
|
snd.fm.buffer[1] = realloc (snd.fm.buffer[1], snd.buffer_size * sizeof (int16));
|
|
if (!snd.fm.buffer[0] || !snd.fm.buffer[1]) return (-1);
|
|
memset (snd.fm.buffer[0], 0, SND_SIZE);
|
|
memset (snd.fm.buffer[1], 0, SND_SIZE);
|
|
}
|
|
|
|
snd.psg.buffer = realloc (snd.psg.buffer, snd.buffer_size * sizeof (int16));
|
|
if (!snd.psg.buffer) return (-1);
|
|
memset (snd.psg.buffer, 0, SND_SIZE);
|
|
|
|
/* Set audio enable flag */
|
|
snd.enabled = 1;
|
|
|
|
/* Initialize sound chip emulation */
|
|
if (PSG_MAME) SN76496_sh_start(zclk, 0, rate);
|
|
else
|
|
{
|
|
SN76489_Init(0, zclk, rate);
|
|
SN76489_Config(0, MUTE_ALLON, VOL_FULL, FB_SEGAVDP, SRW_SEGAVDP, 0);
|
|
}
|
|
|
|
if (FM_GENS) YM2612_Init(vclk, rate, hq_fm);
|
|
else if (!myFM) myFM = YM2612Init (0, 0, vclk, rate, 0, 0);
|
|
|
|
/* Make sound table */
|
|
for (i = 0; i < lines_per_frame; i++)
|
|
{
|
|
float p = (snd.buffer_size * i) / lines_per_frame;
|
|
float q = (snd.buffer_size * (i+1)) / lines_per_frame;
|
|
sound_tbl[i] = p;
|
|
sound_inc[i] = ((q - p) * 1000000) / snd.sample_rate;
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
void system_init (void)
|
|
{
|
|
/* PAL or NTSC timings */
|
|
vdp_rate = (vdp_pal) ? 50 : 60;
|
|
lines_per_frame = (vdp_pal) ? 313 : 262;
|
|
CPU_Clock = (vdp_pal) ? (double)CLOCK_PAL : (double)CLOCK_NTSC;
|
|
miscZ80cycles = (vdp_pal) ? 227 : 228;
|
|
misc68Kcycles = (vdp_pal) ? 487 : 488;
|
|
|
|
gen_init ();
|
|
vdp_init ();
|
|
render_init ();
|
|
sound_init();
|
|
}
|
|
|
|
void system_reset (void)
|
|
{
|
|
aim_m68k = 0;
|
|
count_m68k = 0;
|
|
dma_m68k = 0;
|
|
aim_z80 = 0;
|
|
count_z80 = 0;
|
|
|
|
gen_reset ();
|
|
io_reset();
|
|
vdp_reset ();
|
|
render_reset ();
|
|
|
|
if (snd.enabled)
|
|
{
|
|
fm_reset();
|
|
if (FM_GENS)
|
|
{
|
|
memset (snd.fm.gens_buffer[0], 0, SND_SIZE*2);
|
|
memset (snd.fm.gens_buffer[1], 0, SND_SIZE*2);
|
|
}
|
|
else
|
|
{
|
|
memset (snd.fm.buffer[0], 0, SND_SIZE);
|
|
memset (snd.fm.buffer[1], 0, SND_SIZE);
|
|
}
|
|
|
|
if (!PSG_MAME) SN76489_Reset(0);
|
|
memset (snd.psg.buffer, 0, SND_SIZE);
|
|
}
|
|
}
|
|
|
|
void system_shutdown (void)
|
|
{
|
|
gen_shutdown ();
|
|
vdp_shutdown ();
|
|
render_shutdown ();
|
|
}
|
|
|
|
int system_frame (int do_skip)
|
|
{
|
|
/* update total cycles count */
|
|
dma_m68k += count_m68k;
|
|
|
|
/* reset line cycles counts */
|
|
aim_m68k = 0;
|
|
count_m68k = 0;
|
|
aim_z80 = 0;
|
|
count_z80 = 0;
|
|
lastbusreqcnt = -1000;
|
|
|
|
if (!gen_running) return 0;
|
|
|
|
/* Clear V-Blank flag */
|
|
status &= 0xFFF7;
|
|
|
|
/* Toggle even/odd flag (IM2 only) */
|
|
if (im2_flag) status ^= 0x0010;
|
|
|
|
/* Reset HCounter */
|
|
h_counter = reg[10];
|
|
|
|
/* Point to start of sound buffer */
|
|
snd.fm.lastStage = snd.fm.curStage = 0;
|
|
snd.psg.lastStage = snd.psg.curStage = 0;
|
|
|
|
/* Parse sprites for line 0 (done on line 261 or 312) */
|
|
parse_satb (0x80);
|
|
|
|
/* Line processing */
|
|
for (v_counter = 0; v_counter < lines_per_frame; v_counter ++)
|
|
{
|
|
/* update cpu cycles goal for the line */
|
|
aim_z80 += miscZ80cycles;
|
|
aim_m68k += misc68Kcycles;
|
|
|
|
/* 6-Buttons or Menacer update */
|
|
input_update();
|
|
|
|
/* If a Z80 interrupt is still pending after a scanline, cancel it */
|
|
if (zirq)
|
|
{
|
|
zirq = 0;
|
|
z80_set_irq_line(0, CLEAR_LINE);
|
|
}
|
|
|
|
/* H Int */
|
|
if (v_counter <= frame_end)
|
|
{
|
|
if(--h_counter < 0)
|
|
{
|
|
h_counter = reg[10];
|
|
hint_pending = 1;
|
|
}
|
|
}
|
|
|
|
/* hack for Lotus 2 Recs */
|
|
if (alttiming && !do_skip)
|
|
{
|
|
if (v_counter < frame_end) render_line(v_counter);
|
|
if (v_counter < (frame_end-1)) parse_satb(0x81 + v_counter);
|
|
}
|
|
|
|
/* H retrace */
|
|
status |= 0x0004; // HBlank = 1
|
|
m68k_run(aim_m68k - 404);
|
|
|
|
if (!alttiming && !do_skip)
|
|
{
|
|
if (v_counter < frame_end) render_line(v_counter);
|
|
if (v_counter < (frame_end-1)) parse_satb(0x81 + v_counter);
|
|
}
|
|
|
|
if (v_counter == frame_end)
|
|
{
|
|
/* V Retrace */
|
|
status |= 0x0008; // VBlank = 1
|
|
m68k_run(aim_m68k - 360);
|
|
if (zreset == 1 && zbusreq == 0) z80_run(aim_z80 - 168);
|
|
else count_z80 = aim_z80 - 168;
|
|
|
|
/* V Int */
|
|
vint_pending = 1;
|
|
status |= 0x0080;
|
|
|
|
/* Z Int */
|
|
if (zreset == 1 && zbusreq == 0)
|
|
{
|
|
zirq = 1;
|
|
z80_set_irq_line(0, ASSERT_LINE);
|
|
}
|
|
}
|
|
|
|
status &= 0xFFFB; // HBlank = 0
|
|
|
|
/* Process end of line */
|
|
m68k_run(aim_m68k);
|
|
if (zreset == 1 && zbusreq == 0) z80_run(aim_z80);
|
|
else count_z80 = aim_z80;
|
|
|
|
/* Update sound buffers and timers */
|
|
fm_update_timers (sound_inc[v_counter]);
|
|
snd.fm.curStage = sound_tbl[v_counter];
|
|
snd.psg.curStage = sound_tbl[v_counter];
|
|
}
|
|
|
|
if (snd.enabled) audio_update ();
|
|
return gen_running;
|
|
}
|
|
|
|
#ifdef NGC
|
|
/****************************************************************************
|
|
* softdev - 09 Mar 2006
|
|
*
|
|
*
|
|
* Nintendo Gamecube Specific Mixer from here on in ...
|
|
****************************************************************************/
|
|
extern unsigned char soundbuffer[16][3840];
|
|
extern int mixbuffer;
|
|
extern double psg_preamp;
|
|
extern double fm_preamp;
|
|
extern u8 boost;
|
|
static int ll, rr;
|
|
|
|
void audio_update (void)
|
|
{
|
|
int i;
|
|
int l, r;
|
|
int16 *tempBuffer[2];
|
|
int16 *sb = (int16 *) soundbuffer[mixbuffer];
|
|
|
|
/* get remaining samples */
|
|
/* YM2612 */
|
|
if (FM_GENS)
|
|
{
|
|
int *fmBuffer[2];
|
|
fmBuffer[0] = snd.fm.gens_buffer[0] + snd.fm.lastStage;
|
|
fmBuffer[1] = snd.fm.gens_buffer[1] + snd.fm.lastStage;
|
|
YM2612_Update(fmBuffer, snd.buffer_size - snd.fm.lastStage);
|
|
}
|
|
else
|
|
{
|
|
tempBuffer[0] = snd.fm.buffer[0] + snd.fm.lastStage;
|
|
tempBuffer[1] = snd.fm.buffer[1] + snd.fm.lastStage;
|
|
YM2612UpdateOne (myFM, tempBuffer, snd.buffer_size - snd.fm.lastStage);
|
|
}
|
|
|
|
/* PSG */
|
|
tempBuffer[0] = snd.psg.buffer + snd.psg.lastStage;
|
|
if (PSG_MAME) SN76496Update (0, tempBuffer[0], snd.buffer_size - snd.psg.lastStage);
|
|
else SN76489_Update(0, tempBuffer[0], snd.buffer_size - snd.psg.lastStage);
|
|
|
|
/* mix samples */
|
|
for (i = 0; i < snd.buffer_size; i ++)
|
|
{
|
|
/* PSG */
|
|
l = r = (int) ((double)snd.psg.buffer[i] * psg_preamp);
|
|
|
|
if (FM_GENS)
|
|
{
|
|
l += (int) ((double)snd.fm.gens_buffer[0][i] * fm_preamp);
|
|
r += (int) ((double)snd.fm.gens_buffer[1][i] * fm_preamp);
|
|
snd.fm.gens_buffer[0][i] = 0;
|
|
snd.fm.gens_buffer[1][i] = 0;
|
|
}
|
|
else
|
|
{
|
|
l += (int) ((double)snd.fm.buffer[0][i] * fm_preamp);
|
|
r += (int) ((double)snd.fm.buffer[1][i] * fm_preamp);
|
|
}
|
|
|
|
/* single-pole low-pass filter (6 dB/octave) */
|
|
ll = (ll + l) >> 1;
|
|
rr = (rr + r) >> 1;
|
|
|
|
l = ll * boost;
|
|
r = rr * boost;
|
|
|
|
/* clipping */
|
|
if (l > 32767) l = 32767;
|
|
else if (l < -32768) l = -32768;
|
|
if (r > 32767) r = 32767;
|
|
else if (r < -32768) r = -32768;
|
|
|
|
*sb++ = l;
|
|
*sb++ = r;
|
|
}
|
|
|
|
mixbuffer++;
|
|
mixbuffer &= 0xf;
|
|
}
|
|
#else
|
|
void audio_update (void)
|
|
{
|
|
int i;
|
|
int16 acc;
|
|
int16 *tempBuffer[2];
|
|
|
|
if (FM_GENS)
|
|
{
|
|
int *fmBuffer[2];
|
|
fmBuffer[0] = snd.fm.gens_buffer[0] + snd.fm.lastStage;
|
|
fmBuffer[1] = snd.fm.gens_buffer[1] + snd.fm.lastStage;
|
|
YM2612_Update(fmBuffer, snd.buffer_size - snd.fm.lastStage);
|
|
}
|
|
else
|
|
{
|
|
tempBuffer[0] = snd.fm.buffer[0] + snd.fm.lastStage;
|
|
tempBuffer[1] = snd.fm.buffer[1] + snd.fm.lastStage;
|
|
YM2612UpdateOne (myFM, tempBuffer, snd.buffer_size - snd.fm.lastStage);
|
|
}
|
|
|
|
tempBuffer[0] = snd.psg.buffer + snd.psg.lastStage;
|
|
if (PSG_MAME) SN76496Update (0, tempBuffer[0], snd.buffer_size - snd.psg.lastStage);
|
|
else SN76489_Update(0, tempBuffer[0], snd.buffer_size - snd.psg.lastStage);
|
|
|
|
for (i = 0; i < snd.buffer_size; i += 1)
|
|
{
|
|
int16 psg = snd.psg.buffer[i] / 2;
|
|
|
|
acc = 0;
|
|
acc += FM_GENS ? snd.fm.gens_buffer[0][i] : snd.fm.buffer[0][i];
|
|
acc += psg;
|
|
snd.buffer[0][i] = acc;
|
|
|
|
acc = 0;
|
|
acc += FM_GENS ? snd.fm.gens_buffer[1][i] : snd.fm.buffer[1][i];
|
|
acc += psg;
|
|
snd.buffer[1][i] = acc;
|
|
|
|
if (FM_GENS)
|
|
{
|
|
snd.fm.gens_buffer[0][i] = 0;
|
|
snd.fm.gens_buffer[1][i] = 0;
|
|
}
|
|
|
|
}
|
|
}
|
|
#endif
|
|
|